The invention relates to the field of the motor industry. More specifically, it relates to a hinge assembly for a motor vehicle side swing door having a built-in door stop.
In general, the motor industry uses three elements for fixing and rotating a vehicle side swing door and for holding it in a predefined angular position. These elements are an upper hinge and a lower hinge, both allowing the door to be fixed and to rotate, and a door stop system allowing the door to be held in one or more predefined angular positions. The door stop system also has the function of stopping the door when it has reached its wide-open position.
In some cases, at least one of the two hinges has a door stop device built into it. Such door hinges with built-in door stop are described, in particular, in the following documents: DE-A-29806087, DE-A-19642597, EPA-0 794 308, DE-A-29604089, DE-A-19606186, and EP-A-0 769 600. They in particular comprise a wire spring working in torsion and rolling over a series of rollers.
The hinges with built-in door stop which already exist on the market have various drawbacks. First of all, they are more bulky than conventional hinges because of the presence of the door stop system. The surrounding area of the vehicle has therefore to allow a significant volume so that this type of hinge can be fitted. Furthermore, because the door stop devices have metal parts rubbing against each other, they make a sharp or grinding noise when the door is being manipulated. Motor manufacturers would now like to eliminate this type of noise which is unpleasant to the user. In addition, friction between the metal parts wears the corrosion-proof coating that these might have before they are fitted; this then creates the possibility of these very parts corroding. Finally, with a view to lessening the operating noises of the door stop system, it is common practice for this system to be greased at the end of assembling the vehicle. However, it is periodically necessary to renew this grease during vehicle servicing operations, and motor manufacturers would like to eliminate this greasing stage.
In addition, dirt builds up within the grease during the life of the vehicle, and this may abrade the parts as they rub.
The applicant company, in their French patent application FR 00 01 856, proposed a type of door hinge assembly that to a great extent solved the above problems. In that door hinge assembly, which was of relatively small bulk, a moving knuckle fixed to the door is equipped with two notched metal cams against which a spring held by a fixed knuckle secured to the bodywork of the vehicle and working mainly in bending presses two rollers. A hinge pin articulates the moving knuckle to the fixed knuckle. If the rollers are made of a self-lubricating material such as plastic, then the greasing of the assembly can be dispensed with, although the greasing remains preferable if the rollers are made of metal.
The drawback of this device, however, is that it entails the use of a bending spring, which is a type of spring whose optimum characteristics for this use are more difficult to determine than those of conventional compression springs. It is also more expensive to manufacture. Finally, this bending spring extends over practically the entire height of the door hinge assembly and requires two regions of contact between the door stop mechanism and the fixed knuckle. The bulk of the active part of the door hinge assembly is therefore determined first and foremost by the dimensions that the bending spring needs to have.
The purpose of the invention is to propose a door hinge assembly with a built-in door stop which does not have a bending spring, and the bulk of the active part of which can be reduced still further by comparison with the existing devices.
To this end, the subject of the invention is a vehicle door hinge assembly with a built-in door stop mechanism, of the type comprising a fixed knuckle intended to be secured to the bodywork of the vehicle, a moving knuckle intended to be secured to the door of the vehicle, and means of hinging the said moving knuckle to the said fixed knuckle about a pin, characterized in that it comprises:
a notched cam secured to the said moving knuckle;
a contact surface that can be inserted in one of the notches of the cam during an operation of partially or fully opening the door, carried by a moving part;
elastic means acting on the said moving part to apply the said contact surface against the said cam, these means being secured to the fixed knuckle and comprising:
a compression spring;
a support connected to the fixed knuckle and against which one of the ends of the said compression spring bears; and
a part hinged to the said fixed support about a pin passing through them and constituting the said moving part, against which the other end of the said compression spring bears.
The said contact surface may be a friction surface, possibly designed as an integral part of the said moving part.
The said contact surface may also be a roller which can rotate about a pin.
As a preference, the door hinge assembly according to the invention is characterized in that the said moving knuckle comprises a housing hinged about the pin that hinges the moving knuckle to the fixed knuckle, in that the said housing supports the said cam on its internal wall, and in that the said moving part and its elastic applying means are included in the said housing.
The said housing preferably has a cover isolating it from the external surroundings.
The said cam may be designed as an integral part of the internal wall of the said housing.
The said contact surface may be made of a self-lubricating material.
The door hinge assembly according to the invention may be shaped in such a way as to allow the said door to be taken off its hinges without it being necessary to dismantle the said assembly.
As will have been understood, the invention consists in building a notched cam into the moving knuckle and in causing a contact surface (a simple friction surface or a rotating roller), borne by a moving part built into the fixed knuckle and actuated by means of a compression spring, to bear against this cam. The extent to which the door is open, chosen by the user, determines the notch of the cam in which the contact surface presses. The moving part can move in rotation about a pin passing through the fixed knuckle. Optimally, the cam, the moving part and the means which actuate it are built into a housing secured to the moving knuckle and an internal wall of which bears the cam. This housing is preferably closed off by a cover which completely isolates the active part of the door hinge assembly from the external surroundings.